Massachusetts voters made history by approving a sweeping marijuana decriminalization law on Election Day, but campaign debates are reigniting as communities start to enforce the new rule.

The large margin of victory for the ballot initiative – 65 percent of voters approved the law – is already inspiring similar legislative efforts in other New England states, prompting close attention nationwide to the effects of a less stringent marijuana law.

Massachusetts is not the first state to decriminalize marijuana possession – 12 others have done so. But it is the first since the 1970s to eliminate criminal penalties for possession of small amounts of the drug, even for repeat offenders.

The law makes possession of an ounce or less of pot a civil offense punishable by a $100 fine (with minors required to attend a drug awareness program). At issue are the specifics. Some opponents, including many law enforcement officials, say the law is poorly written and nearly unenforceable. These complaints are accelerating efforts in towns and cities across the state to enact ordinances governing "public consumption," which the law's defenders fear might edge toward recriminalization.

A fine for Mr. Duck

One major concern of some police officials: While marijuana remains an illegal substance, full decriminalization, as is the case in Massachusetts, removes officers' powers of arrest, which means police can't compel offenders to identify themselves.

"If someone is sitting on the front steps of City Hall smoking a bone, you can't do much if they tell you they're Donald Duck," says Terence Reardon, chief of police in Revere, a city of 55,000.

Such complaints are overstated, say decriminalization advocates.

"People have tried to claim that [the identification issue] is a loose end, but in fact it's no different than every other civil citation in Massachusetts, like jaywalking or in some communities drinking in public," says Bruce Mirken, communications director for the Marijuana Policy Project, a national marijuana decriminalization advocacy group that helped coordinate the Massachusetts referendum campaign. "Miraculously, it's a problem with marijuana."

The new Massachusetts law specifically allows communities to draft their own public consumption ordinances, and dozens are considering doing so. The state attorney general's office prepared a model bylaw that would levy an additional $300 fine, the state maximum, on people caught using pot in public.

"We're not making a recommendation one way or the other about whether communities should do this, but if they do they should use this language," says Emily LaGrassa, a spokeswoman for Attorney General Martha Coakley, who opposed the ballot initiative.

But for some communities, such suggestions don't go far enough.

"What we're attempting is to get a city ordinance ... that makes it an illegal and arrestable offense to smoke [marijuana] in public," says Capt. Randall Humphrey of the city of Lowell police department. "We're not sure if we will be able to do it, but that's our goal."

The plan has little chance of success, Captain Humphrey concedes. The Massachusetts Chiefs of Police Association this month e-mailed guidelines to area police chiefs about how Attorney General Coakley is likely to rule on new town bylaws, which her office must approve. The policy update puts arrest provisions off the table.

"We don't believe a bylaw would be approved by the attorney general if it contained an arrest clause," says A. Wayne Sampson of the Massachusetts Chiefs of Police Association.

"Without an arrest component to force identification, there's no point to a bylaw," says Police Chief Richard Stillman of Walpole, a town of about 24,000. He withdrew his plans for a town ordinance after learning of the policy update.

A divisive ordinance

Other towns and cities, though, are moving ahead with efforts to stiffen penalties. The city of Methuen last month became the first to act, raising fines in what the mayor says is an effort to address some "unintended consequences" of the referendum, which some people may interpret as encouraging marijuana use. Mayor William Manzi approves of higher fines, but he says he's been surprised by the "vehemence" of local anger at his efforts and bemoans the divisiveness the issue has stirred up.

"It's all been sort of balkanized at this point," Mr. Manzi says.

In Quincy, early discussions on tougher penalties brought out protestors, marijuana ablaze, to challenge police, says city councilor Kevin Coughlin.

"[Some officials] fear this is the first step toward legalization," he says. "We're going to end up with 351 cities and towns doing 351 different things."

Bill Downing, president of the Massachusetts Cannabis Reform Coalition, discounts such concerns. "The public will see that the sky does not fall," he says. Continuing with efforts to tack on additional marijuana-related penalties "shows a tremendous amount of disrespect to Massachusetts voters who voted to decriminalize," he adds.

The fight is unlikely to end soon. Mr. Downing's organization is listing upcoming town meetings about new public use laws, and at least three are scheduled for next week.

Some hope the Massachusetts legislature will address some of the outstanding enforcement issues. But state Rep. William Brownsberger (D), a longtime researcher of drug issues, doesn't see that as likely.

"Everyone is being cautious politically, and people don't want to be seen as disagreeing with the will of the people," says Representative Brownsberger. While marijuana use is a sensitive issue, he urges perspective. "This is just not our biggest problem, either way."